Relay.



A. fl'.

Y RELAY. APPLICATION FILED SEPT@ 6,'1907.

ELU-25,786. PatentedMay 7, 1912.

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R' R1 Rs Mnsses 'UNITED sTAtrnswrArENT OFFICE.

ARCHIBALD s. CUisiT'r,y or SOHENECTADY, NEW YORK, ASSIGNOR To GENERAL ELECTRIC COMPANY, A CORPORATION orr NEW YORK.

' RELAY.

To all whom t may concern Be it known that I, ARCHIBALD S. CUBrr'r,

vit in its raised position isr much less than the current required to pull it up. In other iyords, there is a considerable ditl'erencebetween its raising` and its dropping current.

An object of my present invention is to provide a relay which Will pull up and drop Within a small change ot` current. Y

In systems of motor vcontrol in .which the speed of the motor is regulated by the amount of resistance -in the motor circuit,

or, if inore'than one motor is used, by also Changing the relation ofthe motors to one another, these changesbeiiig made by acontroller, means often provided forretard-f ing the nioveinentof Vthe controllerin case the currentin the motor `circuit rises higher than a certain value. Aconvenien't fornr'of suoli retarding means consists in an electr-oiiiagnetically operated locking device for the controller, the operation of said lockii'ig device being governed by a relay,t"he actuating,` coil of which is located in the motor circuit. The ordinary form of rela-y, which after itI has pulled up ivill not drop untilthe current through its actuating coil has fallen very considerably, is unsuitable for the motor control system above mentioned, since it will keep the cont-roller'locking device in.,

action long after the motor current has fallen below the'dangerous value.l My iniproved form of relay is, therefore, particu'- larly adapted for use in connection with control systeinsof the above described kind Asince it causes the retardationof the conf. troller only vvliile'the'current in the motor circuit is truly dangerous.

My invention comprises a relay having means-for biasing thecore thereof in a d1-f` lays, of which the following is a specifica-v Speccation of Letters Patent. Patented llIzty 7, 19.12.;

Application ied'septeinber 6, 1907. seriai No. 391,694.'

rectioii Opposite to that in which the actuating coil tends to move it` land means for automatically increasing the lforce exerted by said biasing' means after theI vrelay has pulled up.

through aetuatingcoil has decreased to a value only slightly below that at which it pulled up.

My invention will be more clearly understood from the following description of one 'torni in `which lit maybe embodied, taken iii connection with' the accoml'ianying drawing', in' Which- Figure is a front elevation of a relay having my invention embodied therein; Fig. 2 is a side elevation thereof, aiidFig. 3 shows diagraminatically asiinple motor control system having myiniproved type of relay applied thereto.

lteferringto the drawing,- baok or base .of insulating n-iaterial,` such as sl`ate,upon which the parts of the relay are mounted. The actuating coil ofthe re-` lay is shown at 6. vAn iron core 7 1is mount-.JL

'between fixed collars 13 and 14, a springl servingto hold the. disk 12 yieldingly lYith -sucli an arrangement the 'relay may be made to drop when the current 5 indicates the against the collar 1B; This disk, whenthe' 7 fcore pulls up, bridges fixedvcontacts 1.6 and 17 iii theusual manner.

A collar 18 iixed' on the rod 9 'may engage with the bracket ,11 and serve to limit the downward niovenient of the core. The parts so far described may be of 4any suitable and well knownconstruction.

The movable coi'eis biased for movement downwardly, that is, in a directionopposite to tliatfiii which the actuatiii-gcoil when energized tends to move it, by aspriiigv20' surrounding the rod 9 and placed under tenlsion between the collar 2l adjustably secured to the rod V9, as bya nut 22, and the divided ree enerted by' ioo vlever and cause the same to rock on its pivot,

and its other armv 23 to compress the spring A20, thereby increasing the force tending lto Y make the core ofthe relay drop. The coil 27 maybe provided with aiiiron core 28 secured to or made integral with the bracket 24 in order that the torque exerted on this 'coil may be considerable. The form -of this core is best shown in Fig. 2. The auxiliary coil 27 isnconnected in series with the actuating coil 6 by the heavy conductor 30 and is connected to the Aterminal 31 by a heavy conductor 32. The other end of the actuating coil 6 may be connected to the terminal 33 in a suitable and well known manner, as shown in Fig. 1.` The auxiliary coil 27 and its coperating parts are so de-y signed that, while the. same current -as that required to pull up the relay willV sufficiently energize this coil to operate the belt-crank lever and increase the tension on the spring l.20, these parts will act more slowly than does the actuating coil 6 in pulling up the movable core 7.

In opera-tion when the current in, the'actuat'ing coil 6 has risen to the necessary value, the core is pulled up. The, auxiliary coil 27 being inserie's with'the coil 6 re- 'ceives the same current and attracts the arm .2,6 of the vbell-crank lever, this action, however not taking place until after the core has pulled up, owing to the fact that the coil 27 and its cooperating parts are slower acting than the actuating coil 6 and its coper.

ating' core. Movementv of the bell-crank lever under the influence of the auxiliary coil 27 will increase the tension on the spring 20and thusincrease the force tending tocause the core 7 to drop. lThe effect of thus increasing, after the core 7 has risen, the force exerted on it in opposition to the actuating coil 6 will be to cause the core 7 to drop after a smaller decrease ,in current than it would if the force exerted by the spring 20 were constant. the difference between the current which the relay pulls up'and that at which it drops is decreased. I

In Fig. 3 I have shown a simple motor control system of the 'separately actuated contact type in which the master-switch is.

provided with a locking vdevice which will restrain it from further movement if at any time the current in the motor circuit exceeds al certain value, the operation of the lacking dev-ice being controlled by my new nd improved form of relay 'indicated at A. In Fig. 3 M indicates a'motor; R1, R2 and R3 are resistance sections adapted to be in? troduced into the motor circuit and climi- In other words,

nated therefrom in accelerating; C is a motor controller of the separately actuated contact type adapted to connect the motor to a source of supply and regulate the amount of resistance in the motor circuit: K is a master-switch for governing the op,-

eration of the motor controller; and K1 is i Vrelay A, such systemsV are `well known to those skilled in this art. Suiiice it to say that the master-switch K will in its irst position connect the motor to the line through all t-he resistance and that the successive points on the master-switch provide for the operation of the contactors which cut out the sections of resistance R1, R2 and R3. If during thel movement of the masterswitch the current vin the motor circuit exceeds a certain value, the relay A will pull up and the controller locking device K will prevent further movement of the masterswitch until the current in the motor circuit has fallen sufliciently to allow the relay A. to drop.

`While I have shown only one particular construction in which my invention may be embodied and but a single use therefor, I wish it understood that I realize that many other means may be provided for increasing, after the lrelay has pulled up, the force tending to make it drop, and that it may be used in many other connections. It is my intention to cover all such means in the following claims.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is,-

1. `A relay comprising an actuating co-il, a coi-e movable in the field thereof, means for biasing said core in a direction opposite to that in which the coil when energized tends to move it, an auxiliary coil energized simultaneously with said actuating coil, and means controlled thereby for increasing'the bias on said co-re after the core has moved under the influence of its coil.

2. A relay'comprising an actuating coil, a core movable in the eld thereof, a spring Abiasing said core'in a direction opposite to that in which the coil when energized tends to move, an auxiliary coil energized simul-v taneously` with said actuating coil, l and means operated by said auxiliary-coil for isc 5 core movable 1n biasing said core in a direction opposite to' .increasin1 the t.ension on the spring after the core as moved under' the influence of said actuating coil.

A relay comprising an actuating coil, a

the field thereof, a spring that in which the coil When energized tends to move it, an auxiliary coil in. series withl said actuating coil, and means magnetically 1 0 operated by said auxiliary coil Jfor increasing the tension on -the spring after the core has moved under the influence of saicl actuating'` coil.- l

l 'ay comprising an actuating coil, a 15cm/e no, ble in the fieldv thereof, a spring biasing said core in a direction opposite to that in Which the coil when energized tends to move it, an auxiliary coil in series with said actuating coil, antl a lever device inagneticallyoperatetl hy said auxiliary coil for 'increasing the tension on the spring after the core has moved under the intluence of the actuating coil.

In Witness" whereof, l have hereunto set, 

